Motor cortical functional geometry in cerebral palsy and its relationship to disability

OBJECTIVE

To investigate motor cortical map patterns in children with diplegic and hemiplegic cerebral palsy (CP), and the relationships between motor cortical geometry and motor function in CP.

METHODS

Transcranial magnetic stimulation (TMS) was used to map motor cortical representations of the first dorsal interosseus (FDI) and tibialis anterior (TA) muscles in 13 children with CP (age 9-16 years, 6 males.) The Gross Motor Function Measure (GMFM) and Melbourne upper extremity function were used to quantify motor ability.

RESULTS

In the hemiplegic participants (N = 7), the affected (right) FDI cortical representation was mapped on the ipsilateral (N = 4), contralateral (N = 2), or bilateral (N = 1) cortex. Participants with diplegia (N = 6) showed either bilateral (N = 2) or contralateral (N = 4) cortical hand maps. The FDI and TA motor map center-of-gravity mediolateral location ranged from 2-8 cm and 3-6 cm from the midline, respectively. Among diplegics, more lateral FDI representation locations were associated with lower Melbourne scores, i.e. worse hand motor function (Spearman's rho = -0.841, p = 0.036).

CONCLUSIONS

Abnormalities in TMS-derived motor maps cut across the clinical classifications of hemiplegic and diplegic CP. The lateralization of the upper and lower extremity motor representation demonstrates reorganization after insults to the affected hemispheres of both diplegic and hemiplegic children.

SIGNIFICANCE

The current study is a step towards defining the relationship between changes in motor maps and functional impairments in CP. These results suggest the need for further work to develop improved classification schemes that integrate clinical, radiologic, and neurophysiologic measures in CP.

Hip arthroscopy in staging avascular necrosis of the femoral head

The purposes of this study were to evaluate how accurately current imaging modalities predict the quality of the articular surface in avascular necrosis (AVN) of the femoral head and to provide arthroscopic correlation to current staging modalities. An arthroscopic classification system, derived from the work of Marcus et al, was used to prospectively stage the articular surface in 23 hips with AVN using plain radiographs, magnetic resonance imaging (MRI), and arthroscopy. There was little correlation between all three diagnostic modalities. These findings were not statistically significant. Patients with stage IV disease had the widest variation in the appearance of the articular surface. This study shows poor correlation in the staging of AVN using current imaging techniques. Magnetic resonance imaging has been shown to be inadequate at assessing the articular cartilage. Therefore, either arthroscopy or direct visualization is required for accurate evaluation and staging, especially in stage IV disease.

Replantation of completely amputated distal forearm--1965

Although replantation of completely amputated wrists and forearms is now commonplace, in 1965 the replantation of this "wrist level" amputation was the first reported in the western world. The details of the technique used are contrasted with current standard of care.

Knee flexion contractures: soft tissue correction with monolateral external fixation

We assessed the efficacy of progressive soft tissue distraction using monolateral external fixation in the management of severe knee flexion contractures. We prospectively evaluated 10 knee deformities in seven pediatric patients. After gradual distraction using the modified Orthofix Limb Reconstruction System (LRS), most recent functional status and knee range of motion were determined. This treatment was applied to 10 extremities in seven patients, ranging in age from 2 to 16 years. Diagnoses included arthrogryposis (4), sickle cell disease (1), previous sepsis (1), and congenital pterygium (1). Average preoperative flexion contracture was 80.5 degrees. Each patient achieved full extension. There was one recurrence, despite bracing, which was managed with replacement of the fixator and soft tissue procedures. Management of knee flexion contractures using a monolateral fixator appears to be a viable alternative to extensive release or femoral osteotomy. Long-term follow-up will be essential to assess the overall risk of recurrence and complications.

Reconstruction of longitudinal stability of the forearm after disruption of interosseous ligament and radial head excision (Essex-Lopresti lesion)

We have presented a technique for reconstruction of the central band of the interosseous membrane in conjunction with surgical repair of the distal radial joint and radial head prosthesis. With this technique, we address all three anatomic structures that provide longitudinal stability of the forearm, specifically, (1) radial head replacement, (2) interosseous membrane reconstitution, and (3) TFCC repair.

Botulinum toxin type a neuromuscular blockade in the treatment of equinus foot deformity in cerebral palsy: a multicenter, open-label clinical trial

BACKGROUND

Focal spasticity of the gastrocnemius-soleus muscles causes equinus gait in children with cerebral palsy (CP). Botulinum toxin type A (BTX-A), a neuromuscular blocking agent, reduces muscle tone/overactivity in dystonia, stroke, and CP.

OBJECTIVE

A prospective, open-label, multicenter clinical trial evaluated the long-term safety and efficacy of repeated intramuscular injections of BTX-A on equinus gait in CP children.

METHODS

Nine centers enrolled 207 children. BTX-A injections (4 U/Kg) were given approximately every 3 months (maximum dose 200 U per treatment). Outcome measures included a Physician Rating Scale of gait, ankle range of motion measurements, and the incidence and profile of adverse events.

RESULTS

One hundred fifty-five (75%) of 207 children completed at least 1 year with a total of 302 patient years of BTX-A treatment. The mean duration of BTX-A exposure was 1.46 years per patient. Dynamic gait pattern on the Physician Rating Scale improved in 46% of patients (86/185) at first follow-up. The response was maintained in 41% to 58% of patients for 2 years. Both gait pattern and ankle position improved at every visit. The most common treatment-related adverse events included increased stumbling, leg cramps, leg weakness, and calf atrophy in 1% to 11% of patients. No treatment-related serious adverse events were reported. Only 6% (7/117) of patients with pre- and postantibody samples had both detectable antibodies and a subsequent treatment failure.

CONCLUSION

BTX-A proved both safe and effective in the chronic management of focal muscle spasticity in children with equinus gait.

The role of hip arthroscopy in the evaluation of avascular necrosis

This prospective study evaluated the correlation between plain radiographs, magnetic resonance imaging (MRI), and diagnostic arthroscopy in the staging of avascular necrosis of the femoral head. Fifty-two hips in 46 patients were prospectively staged using radiographic and MRI staging systems. Patients subsequently underwent hip arthroscopy to visualize the articular surface prior to considering salvage of the femoral head and debride delaminated osteochondral fragments. Weighted Kappa analysis revealed only moderate correlation between MRI and plain radiographs (K=.11), MRI and arthroscopy (K=.21), and plain radiographs and arthroscopy (K=.19). Six (46%) of 13 patients with a radiographically apparent subchondral fracture demonstrated collapse of the articular surface at arthroscopy. Four (24%) of 17 hips with >2 mm of collapse of the femoral head on plain radiographs demonstrated fragmentation of the osteochondral surface of the femoral head at arthroscopy. In 5 patients with flattening of the femoral head, 3 patients had delamination of both the femoral and acetabular surfaces. In regard to labral pathology, 5 of 22 post-collapse hips also had large bucket handle tears of the labrum. Arthroscopy of the hip revealed osteochondral degeneration that was not detected by plain radiographs or MRI in 36% of post-collapse femoral heads.

Congenital dislocation of the knee: overview of management options

Congenital dislocation of the knee (CDK) is rare and includes a spectrum of hyperextension disorders of the knee. Early recognition of CDK is important, and careful evaluation is required to rule out associated hip deformity. Early manipulation, combined with splinting and casting, is the mainstay of initial treatment. Patients with seemingly fixed contractures may respond rapidly to serial casting and then can be placed in a Pavlik harness. Severe recalcitrant deformities or late presentation of the deformity may require surgical release. We highlight the importance of diagnostic categorization, show management options, and provide an overview of this rare but clinically significant problem. We present two case reports that illustrate the full range of management options.

Management of spasticity in cerebral palsy with botulinum-A toxin: report of a preliminary, randomized, double-blind trial

In order to evaluate further the efficacy of local intramuscular injections of botulinum-A toxin (BAT-A) in the management of dynamic equinus deformity associated with cerebral palsy, a randomized, double-blind, placebo-controlled study was undertaken. When evaluated using our Physician Rating Scale, 83% (five of six) of patients receiving toxin showed improvement, versus 33% (two of six) receiving placebo. There were no major complications. BAT-A injections appear to be safe and effective in children, and merit further prospective study.

Congenital pseudarthrosis of the tibia treated with free vascularized fibular graft

Management of patients with deformities due to congenital pseudarthrosis of the tibia continues to be controversial. The use of free vascularized fibular grafts in the reconstruction of these deformities appears to be successful in this patient population but is not without potential for significant complications. Long-term evaluation, at least to skeletal maturity, is necessary to judge the success of any procedure done for any pediatric patient. This case illustrates the natural history of the vascularized free fibular graft for congenital pseudarthrosis of the tibia in a young child. Complications of this treatment modality did occur, including probable recurrence and fracture at almost 11 years post-index procedure. However, stable reconstruction leading to fracture union was achieved, and the patient has resumed full activities with little residual deformity.

Effects of peripheral sympathectomy on thermoregulatory vascular control in the rabbit ear

A rabbit ear model of the human digit was utilized to determine the vascular response to peripheral sympathectomy. Vascular responses were evaluated by subjecting chronically instrumented rabbits to a cold stress before and after sympathectomy surgery. The typical response to cold stress is for ear temperatures and auricular cutaneous perfusion to decrease during the cooling phase of the test and to increase toward baseline levels during the rewarming phase after cold exposure. Following peripheral sympathectomy, ear temperatures were significantly increased during both the cooling and rewarming phase of the cold stress test although overall ear perfusion and skin perfusion were not different from sham-operated rabbits. The responses observed in the rabbit ear following peripheral sympathectomy appear to mimic those noted in patients receiving digital peripheral sympathectomies for the treatment of refractory pain and ulceration. Peripheral sympathectomy may result in clinical improvements in patients because it improves both total digital and nutritional cutaneous blood flow. Peripheral sympathectomy in normal rabbit ears does not result in altered perfusion patterns with cold exposure although ear temperature is significantly higher. This pattern of changes suggests that the distribution of extremity perfusion is altered even though overall extremity perfusion and cutaneous perfusion per se are not significantly different from sham-operated controls. Complete sympathectomy was accompanied by a persistent increase in ear temperature and a dissociation between conductance and microvascular perfusion. Auricular conductance was transiently increased and then decreased to levels below preoperative control values. Microvascular perfusion is decreased immediately following amputation/replantation and thereafter increases.

Anatomic and physiologic evaluation of upper extremity ischemia

This study assessed the accuracy of arteriography and laser Doppler perfusion imaging (LDPI) as predictors of digital ischemia and correlated upper extremity symptoms, function, and nutritional flow with arteriographic and laser Doppler assessments. Multiple-level occlusive disease was documented in 25 hands (23 patients) by arteriography. LDPI demonstrated one or more hypoperfused digits in 17 hands. Patient questionnaires were used to assess upper extremity symptoms, pain, cold sensitivity, and function. Spearman correlation coefficients indicated that arteriography is a poor indicator of nutritional perfusion as measured by LDPI. Neither arteriography or laser Doppler perfusion imaging served as an indicator of the severity of cold intolerance. However, upper extremity symptoms and functional status correlated with both laser Doppler measurements and the level of cold sensitivity. Laser Doppler perfusion imaging and arteriographic analysis provide complimentary data in the evaluation of upper extremity ischemia.

Arterial reconstruction for radial artery occlusion

This study was designed to detail the history and symptoms of symptomatic radial artery vaso-occlusive disease and to evaluate the results of radial artery reconstruction. Thirteen patients with symptomatic vaso-occlusive disease of the radial artery unresponsive to management by nonoperative modalities were managed with arterial reconstruction. All cases were treated with reversed interpositional vein grafting from the radial artery in the forearm (end-to-side) to the deep arch distally (end-to-end). Patients completed preoperative and postoperative assessments of symptoms and function, cold sensitivity (cold intolerance), and digital microvascular perfusion (isolated cold stress test evaluation with laser Doppler fluxmetry). At the follow-up examination all vascular grafts were patent, as determined by Allen's testing and Doppler ultrasound. The patients reported symptoms and functional status that demonstrated significant improvement following reconstruction. Microvascular evaluations demonstrated a significant improvement in digital microvascular perfusion as assessed by laser Doppler fluxmetry and digital temperature recordings with a resultant resolution of ischemic pain, numbness, and ulceration.

Role of alpha-1 adrenoceptor subtypes mediating constriction of the rabbit ear thermoregulatory microvasculature

An acute in vivo preparation of the microvasculature of the rabbit ear was used to evaluate the functional role of alpha1 (alpha1)-adrenoceptor subtypes in thermoregulatory microcirculation. The effect of alpha1-adrenoceptor subtype blockade on phenylephrine-induced vasoconstriction was assessed with the alpha1A, alpha1B, and alpha1D-adrenoceptor-selective antagonists 5-methyl-urapidil (10(-8) M), chloroethylclonidine (10(-5) M), and 8-[2-[4(2-methoxyphenyl)-1-piperazinyl]ethyl]-8-azaspirol[4.5]deca ne-7,9-dione dihydrochloride (BMY7378) (10(-6) M), respectively. The results demonstrated that pretreatment of the ear microvasculature with 5-methyl-urapidil or BMY7378 shifted the phenylephrine concentration-response curve rightward and significantly changed the log of the phenylephrine concentration, causing half-maximum stimulation (EC50) in arterioles (p < 0.05). BMY7378 shifted the phenylephrine concentration-response curve of the arteriovenous anastomoses about 100-fold rightward (p < 0.05). All three alpha1-adrenoceptor antagonists eliminated the vasoconstrictive effects of phenylephrine on venules. The results indicate that the ear microvasculature has a heterogenous distribution of alpha1-adrenoceptor subtypes. The alpha1A and alpha1D-adrenoceptor subtypes appear to have a greater influence on constrictive function in arterioles, whereas the alpha1D-adrenoceptor is the dominant constrictor of arteriovenous anastomoses. In general, the alpha1-adrenoceptor does not play a major vasoconstrictor role in venules. Chloroethylclonidine, an irreversible alpha1B-adrenoceptor antagonist, induced contractile responses in the ear microvasculature, probably due to its alpha2-adrenoceptor agonist effects. This study extended our understanding of the adrenergic receptor control mechanisms of a cutaneous thermoregulatory end organ characterized by two parallel perfusion circuits providing nutritional and thermoregulatory functions.

Significance of cold intolerance in upper extremity disorders

After upper extremity injury, pain on exposure to cold (cold sensitivity) is a significant problem. This cross-sectional observational study (1) assesses the incidence and prevalence of cold intolerance, (2) evaluates the relationship between functional status and degree of cold intolerance, and (3) correlates health-related quality of life (HRQL) with symptoms of cold intolerance. Patients in a tertiary care center completed questionnaires to document (1) cold sensitivity, (2) upper extremity pain, symptoms, and function, and (3) HRQL. Cold sensitivity was found to be associated with more functional limitations, greater pain, and reduced HRQL. As the severity of cold intolerance increased, functional limitations and pain increased and HRQL decreased. Cold intolerance has a profound effect on HRQL.

Arterial reconstruction in the ischemic hand and wrist: effects on microvascular physiology and health-related quality of life

Patients were evaluated before and after arterial reconstruction surgery (1) to define the physiology of the digital microcirculation in chronic subcritical ischemia, (2) to demonstrate the short-term effects of successful arterial reconstruction on microvascular flow, and (3) to document the effects of surgery on symptoms, function, and health-related quality of life. Arterial insufficiency was the result of a proximal reconstructible occlusive lesion, 1 or more distal unreconstructible occlusions, and secondary reactive vasospasm. Microvascular physiology was evaluated by monitoring digital temperatures, microvascular perfusion (laser Doppler fluxmetry) and perfusion patterns (laser Doppler perfusion patterns (laser Doppler perfusion imaging). Following successful vascular reconstruction, digital temperatures and microvascular perfusion improved significantly, approaching control levels. Although cold sensitivity was unchanged, symptoms decreased and upper extremity function and health-related quality of life improved after successful proximal reconstruction in patients with 2-level arterial occlusion.

The effect of transdermal nicotine on digital perfusion in reformed habitual smokers

The effects of transdermal nicotine-assisted smoking cessation on digital perfusion and health-related quality of life were assessed in 10 chronic smokers. Components of digital blood flow were evaluated by digital temperature and laser Doppler fluxmetry before, during, and after a standardized cold challenge. Nutritional flow was measured by vital capillaroscopy; a quantitative perfusion profile was obtained by laser Doppler perfusion imaging. A battery of validated measures were used to evaluate health-related quality of life. The microvascular response of smokers was evaluated before smoking cessation and at 2 and 7 days after smoking cessation and was compared with the response of nonsmoking controls. Results demonstrated that a (1) cutaneous microvascular perfusion was lower in smokers than nonsmokers, (2) the acute administration of transdermal nicotine did not decrease cutaneous perfusion, (3) smoking cessation and transdermal nicotine normalized digital microvascular perfusion by 7 days, and (4) transdermal nicotine and smoking cessation did not negatively impact health-related quality of life.

Endogenous nitric oxide influences arteriovenous anastomosis adrenergic tone in the conscious rabbit ear

The role of nitric oxide (NO) in the control of arteriovenous anastomoses (AVAs) has not been studied in vivo in a thermoregulatory end organ. In this study, the effect of local inhibition of NO synthesis by NG-nitro-L-arginine methyl ester (L-NAME) on the microvasculature in the rabbit ear (n=12) was observed in vivo through a chronically implanted ear microvascular chamber. Ear cutaneous blood perfusion (CBP), total auricular arterial flow (TAF), and ear temperature were monitored simultaneously with the direct microvascular observations. Results revealed that intrafacial artery infusion of L-NAME produced significant vasoconstriction of arterioles, AVAs, and venules (p < 0.05). A decrease of ear blood perfusion also was demonstrated by changes of CBP, TAF, and surface temperature. The data provide evidence that basal generation of NO influences the vascular resistance in the thermoregulatory end organ. Moreover, endogenous NO production may be more important in regulating the AVA flow than is flow in other parts of the rabbit ear microvasculature. The effects of NO inhibition on ear microvasculature were not abolished by superior cervical ganglionectomy, indicating that NO production in the rabbit ear is not a neurally mediated mechanism. Further study with a short-term rabbit ear preparation showed that inhibition of NO production with L-NAME enhanced microvascular constrictive responses to extraluminal application of norepinephrine. NO thus appears to play a role of basal vasodilator in opposition to the basal adrenergic vasoconstrictor tone in the rabbit ear.

Alpha adrenoceptors in the rabbit ear thermoregulatory microcirculation

The rabbit ear microcirculation was analyzed in a chronic unanesthetized model to evaluate alpha adrenergic microvascular control in a thermoregulatory end organ. This model allowed direct measurement of microcirculatory responses without the effects of anesthetics or inflammatory responses induced by acute surgical intervention. The ipsilateral facial artery was catheterized for drug injections into the experimental ear. Microvascular diameter changes following stimulation or blockade of adrenoceptor (AR) subtypes were observed directly through a chronic microvascular chamber implanted in the rabbit ear. Vascular alpha1- and alpha2-ARs appear to be distributed differently across the arterioles and AVAs of the rabbit ear. Both alpha1- and alpha2-ARs appear to contribute to vasoconstriction of AVAs in the conscious rabbit ear. In contrast, alpha1-AR's (vs alpha2-ARs) appear to predominate in adrenergically mediated sympathetic vasoconstriction of arterioles.

Effect of cooling on cutaneous microvascular adrenoceptors in vivo in the rabbit ear

Previous studies have suggested that moderate cooling increases the responsiveness of vascular alpha2-adrenoceptors. However, limited information is available documenting the influence of temperature changes on adrenoceptor responses in the microvasculature of thermoregulatory organs (e.g., the human digit and the rabbit ear) subjected to a wide range of temperatures. In the present study, the effect of local cooling (24 degrees C) on cutaneous microvascular adrenoceptors in the ear was observed in vivo in male New Zealand White rabbits (total: 66 ears). The rabbit ear was studied in a temperature-controlled tissue bath; the ear preparation was pretreated with terazosin (an alpha1-adrenoceptor antagonist) (10(-5) M) or a combination of terazosin (10(-5) M) and propranolol (a beta-adrenoceptor antagonist) (10(-6) M). The microvascular diameter responses of the ear to norepinephrine (10(-11)-10(-4) M) then were determined at 24 or 34 degrees C, respectively, to determine the influences of low temperature on adrenoceptor responses to norepinephrine stimulation. The results demonstrated that low concentrations of norepinephrine induced vasodilation in arterioles and arteriovenous anastomoses. This vasodilation was followed by vasoconstriction with an increased concentration of norepinephrine in animals with alpha1-adrenergic blockade at 34 degrees C. Moderate tissue cooling increased the microvascular maximal response of the rabbit ear to norepinephrine and abolished the vasodilatation induced by a low concentration of norepinephrine. There was no significant difference in the microvascular response to norepinephrine between the two temperature conditions after simultaneous blockade of alpha1-adrenoceptors and beta-adrenoceptors. Data from the present study indicate that moderate cooling does not enhance the responsiveness of alpha2-adrenoceptors to norepinephrine. In contrast, cooling reduced the beta-adrenergic activity of arterioles and arteriovenous anastomoses after norepinephrine stimulation.

THE FIBULA-FLEXOR HALLUCIS LONGUS OSTEOMUSCULAR FLAP

Limb salvage after loss of bone and soft tissue may require many operations to obtain soft-tissue cover and bony continuity. We describe a fibula-flexor hallucis longus osteomuscular flap which can provide both soft tissue and bone in a single stage. The flap is based on the peroneal vessels and is covered by a split-thickness skin graft.

We report the results in five patients with an average bone defect of 8.3 cm and soft-tissue and skin loss. All regained a normal gait on the donor side; four had clinical and radiological union with excellent soft-tissue cover, but one required later amputation due to diffuse coagulopathy.

The flap provides free vascularised bone with muscle cover. It has a dependable, long pedicle with minimal morbidity at the donor site, and allows monitoring of the vascularity of the fibular graft.

The fibula-flexor hallucis longus osteomuscular flap

Limb salvage after loss of bone and soft tissue may require many operations to obtain soft-tissue cover and bony continuity. We describe a fibula-flexor hallucis longus osteomuscular flap which can provide both soft tissue and bone in a single stage. The flap is based on the peroneal vessels and is covered by a split-thickness skin graft. We report the results in five patients with an average bone defect of 8.3 cm and soft-tissue and skin loss. All regained a normal gait on the donor side; four had clinical and radiological union with excellent soft-tissue cover, but one required later amputation due to diffuse coagulopathy. The flap provides free vascularised bone with muscle cover. It has a dependable, long pedicle with minimal morbidity at the donor site, and allows monitoring of the vascularity of the fibular graft.

Acute effects of periarterial sympathectomy on the cutaneous microcirculation

The clinical effects of peripheral sympathectomy on patients with vaso-occlusive disease are often dramatic and include relief of pain, improved quality of life, and healing of ulcers. Peripheral periarterial sympathectomy is known to increase skin temperature and to maximize the nutritional component of peripheral blood flow, but the pathophysiology of vaso-occlusive disease and the physiologic mechanisms of this treatment are unknown. In this study, the acute effects of periarterial sympathectomy were directly observed in a rabbit ear model of digital microcirculation (arterioles, arteriovenous anastomoses, and venules). The effects of periarterial sympathectomy on cutaneous perfusion and total flow were also examined using laser Doppler perfusion imaging and digital temperature measurements. The central auricular artery became dilated (50-100%) immediately after sympathectomy; the arterioles, arteriovenous anastomoses, and venules dilated to 165, 156, and 223%, respectively, at 30 minutes and to 187, 174, and 204%, respectively, at 60 minutes, relative to their baseline diameters prior to sympathectomy. Laser Doppler perfusion imaging values and ear temperatures were noted to increase after sympathectomy (8.9%, 3 degrees C), although the core temperature of the rabbit did not change. Thus, acute periarterial sympathectomy can (a) effectively reduce the vascular tone of the distal microvasculature and (b) increase total microcirculatory perfusion-cutaneous and thermoregulatory-by both venular and arteriolar dilation. Periarterial sympathectomy has the clinical potential to increase nutritional blood flow, thereby ameliorating the signs and symptoms of ischemia associated with thermoregulatory abnormalities. Dilation of the arteriovenous anastomoses, with a subsequent reduction in vascular resistance, may contribute to the increased cutaneous temperature noted after sympathectomy.

Management of vasospastic disorders of the hand

Vasospastic disorders of the upper extremity are common and often difficult to treat. Using the proposed classification system (Table 2) allows management based upon pathologic condition, physiologic staging, and response to treatment. Identifying patients in this way also helps in determining which treatments are most appropriate. The basic approach to management includes environmental and behavioral modifications including cessation of tobacco use, protection of hands, and avoidance of situations that trigger the vasospastic response. Pharmacologic therapy may provide good results in a majority of patients. Surgical intervention is reserved for patients with vaso-occlusion, ischemia, and refractory symptoms in spite of attempts at medical management. Surgical options include vascular reconstruction, peripheral sympathectomy, or a combination of techniques. The goal of medical and surgical management is to increase total or nutritional blood flow in the digits.

The painful hand

RSD can be approached using objective criteria in a logical and systematic fashion. Frustration during treatment is common because (1) the pathophysiology of RSD is incompletely understood, (2) there is significant variation in presentation because of disparate premorbid anatomy and physiology, and (3) the natural history may be affected by incomplete treatment. Therapeutic efforts that theoretically should be effective may fail, and a trial-and-error approach is often mandatory. In spite of vigorous intervention using all known strategies, patients may continue to have pain and disability that progresses to stiffness and arthrofibrosis. Early recognition and prompt intervention, however, provide the best opportunity for clinical improvement.

The pharmacologic approach to the painful hand

The management of reflex sympathetic dystrophy with oral, topical, and parenteral medications is complex. This article outlines the pharmacologic options available to treat dystrophic pain, provides an overview of mechanisms-of-action, and defines relative indications for administration.

Control of arteriovenous anastomoses in rabbit ear model of digital perfusion

The arteriovenous anastomoses (AVA) of the cutaneous microcirculation of the hands and feet are fundamental determinants of thermoregulatory blood flow and may be involved in cold intolerance. These direct microvascular studies are an initial characterization of adrenergic receptor subtypes participating in control of AVA in the ears of anesthetized male New Zealand White rabbits. Adrenergic alpha 1-stimulation with phenylephrine produced AVA constriction, whereas terazosin (an alpha 1-antagonist) produced dilation and attenuated the responses to phenylephrine. Adrenergic alpha 2-stimulation with UK-14304 produced constriction of the AVA, whereas atipamezole (an alpha 2-antagonist) produced dilation and attenuated the responses to UK-14304. When equimolar concentrations of antagonists were studied, the AVA dilation produced by alpha 2-blockade was greater than that produced by alpha 1-blockade. Norepinephrine (a mixed alpha 1- and alpha 2-agonist) also produced vasoconstriction, which was attenuated by both prazosin (an alpha 1-antagonist) and atipamezole. In summary, 1) AVA contain a heterogeneous mixture of both alpha 1- and alpha 2-receptors, and 2) alpha 2-receptors may have a greater influence than alpha 1-receptors on overall tone in AVA.

Neuromuscular blockade in the management of cerebral palsy

Neuromuscular blocking agents-45% alcohol, 4% to 6% aqueous phenol, local anesthetics, and botulinum A toxin-have been used for many years in the evaluation and management of spasticity and movement disorders in children with cerebral palsy. Recent reports suggest that longer-acting neuromuscular blocking agents may impact positively on the natural history of dynamic deformity and improve health-related quality of life. This review includes the mechanism of action, techniques, indications, complications, and clinical outcomes associated with these agents.

The histological effect of barrier vein wrapping of peripheral nerves

Twenty-four Sprague-Dawley rats underwent exploration and exposure of the sciatic nerve, followed by sham isolation, irrigation, and subsequent wound closure (Group 1); barrier vein wrapping of the nerve using glutaraldehyde-preserved allograft inferior vena cava (Group 2); or barrier vein wrapping of the nerve with femoral vein autograft from the contralateral extremity (Group 3). Four months later, the rats were sacrificed and the nerves fixed in situ in buffered glutaraldehyde. Sections proximal, mid-portion, and distal to the barrier and vein wrap were fixed with osmium tetroxide, epon embedded, stained with toluidine blue, and studied under x200 and x400 light microscopy. Epineural scar formation increased 10 times in Group 2, compared to Group 3 (p < 0.0001). Epineural thickness and the number of degenerating axons did not differ significantly among all groups. Inflammatory cells in Group 2 increased 100 times, compared to Group 3 (p < 0.0001). Continuing with the underlying epineural layer was apparent grossly and microscopically with all allografts, but with no autografts. Thus, glutaraldehyde-preserved allograft vein wraps appear to incite a marked inflammatory response, with epineural scarring and adherence to the underlying nerve, while autograft vein wraps do not.

The microcirculatory effects of peripheral sympathectomy

Microvascular physiology following peripheral artery sympathectomy was evaluated in seven hands with refractory pain (n = 7) and ulceration (n = 7) by serial isolated cold stress testing, which measures digital temperature and cutaneous perfusion (laser Doppler fluxmetry). All patients (n = 6) had vasospasm (secondary Raynaud's phenomenon) and arteriographically proven digital and palmar occlusive disease. Microcirculatory flow responses were correlated with symptoms and signs (including ulcer healing) before and after (2-8 weeks, 12-15 weeks, and 24 weeks) peripheral sympathectomy. Baseline data were compared with those of controls (n = 7 extremities). Following surgery, all seven hands had diminished pain; six had ulcer healing and one had ulcer reduction. Isolated cold stress testing demonstrated abnormalities in temperature and laser Doppler fluxmetry response between patients and controls. Although total flow (reflected by temperature) was not significantly increased after surgery, peripheral sympathectomy increased nutritional flow in these patients with combined vasospastic vessels and occlusive injury. The clinical changes observed following peripheral sympathectomy appear to be related to postsurgical correction of abnormal arteriovenous shunting and to improved nutritional blood flow to ischemic areas. This accounts for the resultant diminution of pain and healing of ulcers observed in these patients after surgery.

A rabbit ear model for cold stress testing

A rabbit ear model resembling the human digit was studied to determine the vascular response of the rabbit ear to a cold stress. Following moderate cooling (10 minutes at 5 degrees - 8 degrees C), auricular blood flow and cutaneous perfusion were reduced. This decrease was reversed by 30 minutes of warming. The response in the rabbit ear to cold stress is similar to that of normal human digits. The similarities between the control of the circulation in human digits and rabbit ears may result from the similarities in digital and auricular vascular receptors and receptor subtypes. Verification of the rabbit model provides an experimental method for obtaining important data regarding digital pathophysiology and the treatment of cold intolerance. Further study with this model will provide clinically relevant information regarding the pathophysiology of digital thermoregulatory abnormalities.

Decreased microvascular perfusion in the rabbit ear after six hours of ischemia

The cellular injury produced by reperfusion of ischemic tissue with oxygen-rich blood has been studied in numerous tissues but has not been investigated extensively in thermoregulatory tissue. This study was designed (a) to compare 4 and 6 hours of ischemia to document the evidence of impaired capillary perfusion after resumption of blood flow (reperfusion injury) in a thermoregulatory end organ (the rabbit ear), and (b) to examine, with use of vital capillaroscopy (VC) and laser Doppler flowmetry (LDF), the altered microvascular blood flow in the rabbit ear after ischemia and reperfusion. One ear from each of five rabbits underwent warm ischemia for 4 hours. VC showed no deficits of capillary perfusion in these ears after reperfusion; LDF measurements in both ears also demonstrated no significant difference between control and reperfusion blood flow. One ear from each of eight additional rabbits underwent 6 hours of warm ischemia. LDF values were significantly reduced in the ischemic ear after reperfusion as compared with baseline measurements for that ear and as compared with the control ear. VC showed arrested perfusion and static plasma gaps within three to five capillaries per high-power field (an area of 300 x 500 microns) in the ischemic ear and good perfusion of all vessels in the contralateral control ear. This evidence of reperfusion injury in a thermoregulatory end organ may help to explain the poor functional result that often occurs after replantation of an amputated digit.

Microvascular response in the rabbit ear to total body cooling: a model for study of human digits

Conditions such as Raynaud's disease, cold intolerance following digit replantation, and reflex sympathetic dystrophy are all exacerbated by diminished blood flow in the digits. The rabbit ear, being similar to the human digit, is an excellent model for studying microvascular responses during thermoregulation and was used in this study of microcirculatory changes during total-body cold stress. In eight rabbits a window was placed in one ear each, and the underlying vascular beds were photographed with the unanesthetized animal at room temperature (23 degrees C) and in a cold room (6 degrees C). Luminal arterial diameters constricted more than venular diameters during cold stress (39.6% vs. 16.5%, respectively, of the control diameters; P = 0.014). All responses were linear; the slopes of the regression lines were significantly different between arterioles and venules (P < 0.0001). This study suggests that decreased circulation in response to cold is due to decreases in the diameter and number of vessels available for perfusion, as predicted by the Poiseuille equation.

Arthroscopic categorization of intercarpal ligamentous injuries of the wrist

Recent advances in our knowledge of wrist ligamentous anatomy, as well as improvements in arthroscopic techniques, permit the diagnosis and treatment of a wide variety of wrist injuries. The authors review current concepts in wrist ligamentous anatomy, patterns of instability, and the role of the arthroscope in the evaluation and treatment of such instability. Specifically, wrist portal anatomy and techniques of arthroscopic treatment of patients with partial and complete intercarpal ligament injuries are described. Chronic complete injuries are a contraindication of arthroscopic treatment. The authors conclude that wrist arthroscopy provides a valuable method of diagnosing and treating partial and complete intercarpal ligamentous injuries.

Patterns of microvascular response associated with reflex sympathetic dystrophy of the hand and wrist

The diagnosis of reflex sympathetic dystrophy is based on clinical presentation and often the presence of a positive three-phase technetium bone scan result. This study compared vasomotor control patterns between reflex sympathetic dystrophy patients with positive bone scan results and those with negative results. Both groups showed similar vasomotor responses to isolated cold stress testing--warm, cold, and transitional patterns of response were identified in both groups. Thus, this study demonstrates that a positive technetium bone scan result does not correlate with vasomotor disturbances in patients with reflex sympathetic dystrophy of the hand.

Management of cerebral palsy with botulinum-A toxin: preliminary investigation

Use of intramuscular botulinum-A toxin (Botox) to produce neuromuscular blockade has been effective in treating certain ocular and facial muscular imbalances as well as spasmodic torticollis. In this preliminary open study, the effectiveness of intramuscularly injected Botox on the muscular imbalances of cerebral palsy was assessed in 27 pediatric patients. Each patient had "dynamic deformities" unresponsive to other treatment, and operation was the only other realistic alternative. The dose of Botox was calculated on a unit/body weight basis. In ambulatory patients, clinical changes in gait were assessed by a physician's rating scale. Reduction in spasticity became apparent in 12-72 h after injection; the effect of Botox after target threshold was reached lasted 3-6 months. No major side effects occurred. Botox may prove a useful adjuvant in conservative management of the spasticity of cerebral palsy. Successful management with these injections may allow delay of surgical intervention until the child is older and at less risk of possible complications, including the need for repeated surgical procedures.

Reflex sympathetic dystrophy in an adolescent

The clinical course of an adolescent with reflex sympathetic dystrophy of the foot is presented. The potential problems of establishing objective diagnostic criteria for reflex sympathetic dystrophy are related to the dynamic nature of the disorder. Serial radiographic studies, radionuclide scans, and quantitative densitometric measurements may be useful in combination; isolated cold stress testing and laser Doppler fluxmetry are useful in assessing thermoregulation and vasomotor instability. A regimen of amitriptyline and phenytoin plus physical therapy with stress loading was useful in this patient, but in many patients the course is progressive, leading to chronic pain and debilitation.

Management of valgus hindfoot deformity in pediatric cerebral palsy patients by medial displacement osteotomy

To determine the clinical indications and efficacy of medial displacement osteotomy of the calcaneus in management of hindfoot valgus, we evaluated 18 feet (ten patients) prospectively. Average follow-up was 42 months; minimum follow-up was 24 months. The osteotomy was performed parallel to the subtalar joint through a lateral incision; the distal fragment was displaced > or = 50% and transfixed with two parallel pins for approximately 4 weeks. Analysis of hindfoot stability, foot position, and extremity function yielded excellent (n = 17) or fair (n = 1) results. Varus overcorrection in the "fair" foot required a closing wedge osteotomy.

Stress testing in the evaluation of upper-extremity perfusion

Stress testing is an important element in the evaluation of upper extremity vascular perfusion. Advances in noninvasive testing provide mechanisms to evaluate the static structural characteristics of the arterial system, to define patient and nonpatient vessels to identify areas of thrombosis or occlusion, to evaluate arterial wall motility and elasticity, and to observe the nutritional capillary bed. To understand upper-extremity vascular function, however, some form of stress testing is crucial. The techniques discussed previously continue to evolve and serve only as examples of the potential of noninvasive tests evaluated before, during, and after stress. Stress testing provides techniques that allow us to understand the functional components of vascular perfusion and to monitor our attempts at interventions.

New skeletal muscle model for the longitudinal study of alterations in microcirculation following contusion and cryotherapy

This preliminary report describes the use of a rat model developed to study in vivo the effect of anesthesia, contusion, and cryotherapy on skeletal muscle microcirculation by use of an implanted chamber. The diameters of arterioles and venules within the chamber were determined by photomicroscopy in the contusion study and by compound videomicroscopy in the anesthesia study; microvascular perfusion was determined by laser Doppler fluxmetry (LDF). Combined ketamine and xylazine anesthesia significantly reduced (P < 0.05) arteriolar and venular diameters by 32.4% and 37.8%, respectively, and average LDF measurements by 36.1%. Contusion significantly increased arteriolar diameters over baseline values (P < 0.05); cryotherapy did not alter arteriolar diameters but increased venular diameters (P < 0.05). It is hypothesized that this increase in venular diameter may, by increasing the surface area available for reabsorption, explain one mechanism by which cryotherapy decreases the edema of contusion. Use of this model should help to advance the understanding of microcirculatory dynamics following contusion and cryotherapy.

Measurement of hand microvascular blood flow with isolated cold stress testing and laser Doppler fluxmetry

Isolated cold stress testing applies cold thermal stress to an extremity for noninvasive study of skin surface temperature as an index of digital microcirculation. In this study, laser Doppler fluxmetry was combined with isolated cold stress testing to examine the relationship between digital thermoregulation (measured by isolated cold stress testing) and digital microcirculatory blood flow (measured by laser Doppler fluxmetry) in 50 healthy men and women. After a 5-minute baseline period, both hands were subjected to cold stress (average, 8 degrees C) for 20 minutes and then returned to room temperature for 20 minutes. Digital temperatures and laser Doppler measurements were graphed to document individual responses. The 25 women had lower digital temperatures, lower laser Doppler fluxmetry values, and less average rewarming than the 25 men. Statistical cluster analysis revealed a cold pattern, found predominantly in women, and a warm pattern, found predominantly in men. These patterns of response may help to elucidate the pathogenesis of the vascular occlusive syndromes occurring predominantly in women.

Response of rabbit ear microvasculature to total body cooling as observed through a new implantable window

A new implantable window was developed in order to study the native microcirculation of the rabbit ear. The responses of the ear microvasculature to total body cooling were studied before and after implantation of the window. No differences were found between arteriolar and venular vasoconstriction with cooling before and after implantation of the window. Arteriolar constriction was significantly greater than the venular response both before and after placement of the window (P = 0.014). Surface skin temperature of the instrumented and control ears was similar at room temperature (35.2 +/- 2.6 versus 36.1 +/- 1.0 degrees, respectively; P = 0.280); however, the instrumented ear was slightly warmer during cooling (17.9 +/- 1.9 versus 15.2 +/- 3.1 degrees; P = 0.024), suggesting increased blood flow in the instrumented ear. Details of construction and implantation of the window are described.

Ligamentous injuries of the wrist in athletes

The athlete's wrist is particularly prone to injury. Although many wrist injuries are dismissed as sprains or strains, a number of these injuries involve significant ligamentous damage that can lead to chronic carpal instability. A complete knowledge of the carpal ligamentous anatomy and classification of wrist instability patterns is necessary for the adequate diagnosis and treatment of these injuries.

Development of a new rabbit ear model for the longitudinal study of digital pathophysiology

A rabbit ear model has been developed in which arterial pressure, auricular blood flow conductance, and microvascular perfusion can be followed continuously in conscious animals. Conductance is measured with a transit-time flow probe placed around the auricular artery, arterial pressure is measured with an abdominal aortic catheter, and cutaneous microvascular perfusion is assessed using laser Doppler fluxmetry. Placement of a femoral vein catheter permits administration of vasoactive substances. To date, rabbits have been instrumented for 90 days or longer. Auricular and abdominal arterial pressures were equal, permitting the calculation of auricular artery conductance. Microvascular perfusion as measured by laser Doppler fluxmetry followed changes in overall blood flow. The presence of postsynaptic alpha 2-receptors was confirmed by determining auricular conductance before and after the administration of intravenous alpha-agonists. The development of this unique model will help to advance the understanding of the pathophysiology of human digital thermoregulatory vascular abnormalities.